From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
List of six key engine test criteria including reliability, smoothness, and power output.
| Identifier | ExFiles\Box 154a\3\ scan0207 | |
| Date | 27th March 1936 guessed | |
| (1) Mechanical Reliability. It has been established that 25 hours full throttle on the test bed subjects the reciprocating parts to much the same fatigue as 15,000 to 20,000 miles' high speed running in France. The test used was - 30 mins. at 90% max. revs. full power. 25 " " 95% " " 5 " " max. revs. full power in every hour. (2) Smoothness. An indication of engine smoothness can often be obtained from the ignition advance characteristics. If less than 20° total advance is required it may be suspected that the engine will be rough. High speed roughness may be due to flywheel periods; torque reaction and idling roughness to too much turbulence. (3) Silence. Gear noise, tappets, pistons, etc. should be checked. (4) Power output. It should be estimated if this agrees with the valve area and camshaft characteristics, together with the air consumption and measured mechanical efficiency. (5) Ignition Advance Characteristics. These should be ascertained, together with the variation necessary to produce a 2% drop either way. (6) Filters. The bearings should indicate the efficiency of these. | ||